Classifications

• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
  • C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
  • C12Q1/34—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving hydrolase
  • C12Q1/44—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving hydrolase involving esterase
• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
  • C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
  • C12Q1/60—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving cholesterol
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
  • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
  • G01N33/92—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving lipids, e.g. cholesterol, lipoproteins, or their receptors
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S435/00—Chemistry: molecular biology and microbiology
  • Y10S435/975—Kit

Definitions

• the present invention relates to a method for the assay of components in very low-density lipoprotein (VLDL) in blood. More particularly, it relates to a method for the selective assay of cholesterol in VLDL.
• VLDL very low-density lipoprotein
• lipoprotein serum contains four kinds of lipoprotein, i.e. high-density lipoprotein (HDL), low-density lipoprotein (LDL), very low-density lipoprotein (VLDL) and chylomicron (CM).
• HDL high-density lipoprotein
• LDL low-density lipoprotein
• VLDL very low-density lipoprotein
• CM chylomicron
• Fractionation of lipoprotein has been carried out by means of an ultracentrifugal operation from ancient days. The operation therefor needs skillfulness and is conducted by installing an ultracentrifuge separately and centrifugation is carried out for several days. Therefore, it was not possible to treat many samples. Besides that, there are a method where lipoprotein is separated by electrophoresis and amount of protein is determined and a method for the assay of cholesterol for each lipoprotein by HPLC but they are lacking in processing ability and, in addition, expensive apparatus in addition to the popular automatic analysis apparatus is necessary.
• an insoluble aggregate is formed during the reaction resulting in turbidity which affects the assayed result and causes the assay error and, further, reaction cell is polluted by the aggregate which significantly affects the assayed result for other biochemical items being assayed at the same time.
• Such an art comprises a device for assaying method and common technique for inhibiting the enzymatic reaction by the formation of complex and aggregate and the bad affection inherent to the turbidity is not solved.
• An object of the present invention is to provide a method for a selective assay of components, particularly cholesterol, in VLDL which is one of serum lipoproteins.
• the present inventors have carried out intensive investigations for a quantitative determination of the components in VLDL in biological samples, particularly in serum, using a commonly used automatic analysis apparatus without separation by means of centrifugal separation and without forming turbidity by complex or aggregate in the reaction solution.
• the present invention comprises (1) a method for assaying the components in very low-density lipoprotein (VLDL) fraction by an enzymatic reaction, the method which is characterized in that a reaction by enzyme showing a high specificity to VLDL is carried out under the control by addition of at least calixarene or a salt thereof; (2) the method for assaying the component in VLDL according to the above (1) wherein the reaction by enzyme is carried out under the control by addition of at least albumin in addition to the calixarene or the salt thereof; (3) the method for assaying the component in VLDL according to the above (1) wherein the reaction by enzyme is carried out under the control by addition of at least basic amino acid in addition to the calixarene or the salt thereof; (4) the method for assaying the component in VLDL according to the above (1) wherein the reaction by enzyme is carried out under the control by addition of at least albumin and basic amino acid in addition to the calixarene or the salt thereof; (5) the method for assaying the component in V
• LPL or CE cholesterol ester hydrolase
• LPL or CE which is derived for example from Chromobacterium viscosum or Pseudomonas is preferably used since it dominantly reacts with VLDL as compared with other lipoproteins.
• an enzyme which is modified, for example, with an object of stabilization of the enzyme may be used so far as it is an enzyme dominantly reacting with VLDL and able to achieve the object of the present invention. Therefore, there is no particular limitation whether or not it is modified.
• calixarene and a salt thereof such as calix[4]arene, calix[6]arene, calix[8]arene, calix[4]arene sulfate, calix[6]arene sulfate, calix[8]arene sulfate, calix[4]arene acetate, calix[6]arene acetate, calix[8]arene acetate, carboxycalix[4]arene, carboxycalix[6]arene, carboxycalix[8]arene, calix[4]areneamine, calix[6]areneamine and calix[8]areneamine.
• Appropriate one may be selected therefrom and the concentration for actual use may be decided by simple experimental repetition.
• One or more kind(s) of calixarene may be used for the method of assay according to the present invention.
• albumin in addition to calixarenes.
• LPL or CE having selectivity to VLDL inherently acts on HDL as well.
• LPL or CE shows a high reactivity with HDL and VLDL while it weakly reacts with LDL.
• albumin is added, the reactivity of LPL or CE with HDL is suppressed whereupon the enzyme reacts only with VLDL.
• Bovine serum albumin is usually used as albumin although there is no particular limitation for its origin. Concentration in actual may be determined by experiments and the range of 0.05 ⁇ 10% is usable.
• arginine there may be usually used arginine, arginine hydrochloride, lysine, lysine hydrochloride, histidine, histidine hydrochloride, hydroxylysine and hydroxylysine hydrochloride and they may be appropriately selected and used. Concentration in actual may be determined by experiments and the range of 0.1 ⁇ 1,000 mmol/L is usable.
• One or more kind(s) of basic amino acid may be used for the method of assay according to the present invention.
• assay of cholesterol is carried out in accordance with the common method for assaying the total cholesterol.
• a method where cholesterol is made to react with cholesterol dehydrogenase (CDH) and oxidized coenzyme and the reduced coenzyme which is a product of the said reaction is spectrometrically detected.
• CDH cholesterol dehydrogenase
• CDH requires hydrazine for potentiating the quantifying property of the reaction [an art of Japanese Patent Laid-Open No. 05/176,797 (Dec. 27, 1991)] and is used by combining with other conditions such as activator and stabilizer.
• Known art may be applied therefor.
• activators and stabilizers are nonionic surface-active agents and cholic acids. Concentration thereof in actual may be determined by experiments.
• the oxidized coenzyme are oxidized ⁇ -nicotinamide adenine dinucleotide (NAD), oxidized thio-nicotinamide adenine dinucleotide (t-NAD), oxidized ⁇ -nicotinamide adenine dinucleotide phosphate (NADP) and oxidized thio-nicotinamide adenine dinucleotide phosphate (t-NADP).
• NAD oxidized ⁇ -nicotinamide adenine dinucleotide
• t-NAD oxidized thio-nicotinamide adenine dinucleotide phosphate
• t-NADP oxidized thio-nicotinamide adenine dinucleotide phosphate
• the present invention further provides a reagent kit equipped with reagents necessary for carrying out the above-mentioned method for assaying the components in VLDL according to the present invention.
• the reagent kit of the present invention contains one or more substances selected at least from calixarenes, albumin and basic amino acids and is a reagent kit for the assay of the components in the manufactured VLDL.
• the following reagents were prepared. With regard to the samples, 30 human serum examples from volunteers were used. The assay was carried out using an Automatic Analysis Apparatus, Type 7170, of Hitachi. Firstly, 180 ⁇ L of the reagent 1 were added to 18 ⁇ L of the sample followed by keeping at 37° C. for 5 minutes and, at that stage, absorbance 1 was measured at the dominant wavelength of 340 nm and non-dominant wavelength of 570 nm. Then 60 ⁇ L of the reagent 2 were added followed by keeping at 37° C. for 5 minutes and, at that stage, absorbance 2 was measured at the dominant wavelength of 340 nm and non-dominant wavelength of 570 nm. Difference between the absorbance 1 and the absorbance 2 was calculated and converted to the amount of the sample using a control of known VLDL-cholesterol concentration as a standard solution.
• the control method was in accordance with a method by Havel et al. [Have R J, Eder H A, Bragdon J H: The distribution and chemical composition of ultracentrifugally separated lipoproteins in human serum, J. Clin. Invest., 34, 1345 ⁇ 1353 (1955)]. Cholesterol in the fractionated VLDL fraction was determined by a T-CHO reagent L “Kokusai” (International Reagents Corporation). Table 1 shows the result of assay using 30 cases of human serum. In the present method, the correlation coefficient was 0.993 (p ⁇ 0.05) and the result was good well coinciding with the control method.
• Reagent 1 HEPES buffer (pH 7.5) 50 mmol/L Hydrazinium dichloride 60 mmol/L Sodium cholate (activator) 0.4% Oxidized ⁇ -nicotinamide adenine dinucleotide 6.0 mmol/L Calix[8]arene sulfate 10.0 mmol/L Bovine serum albumin 2.0% Arginine 200 mmol/L Reagent 2 HEPES buffer (pH 8.0) 50 mmol/L Cholesterol dehydrogenase 20 U/mL Cholesterol ester hydrolase (derived 3 U/mL from Pseudomonas sp.) Sodium cholate 0.1%
• the following reagents were prepared. With regard to the samples, 10 human serum examples from normal healthy persons were used. The assay was carried out using an Automatic Analysis Apparatus, Type 7170, of Hitachi. Firstly, 180 ⁇ L of the reagent 3 were added to 15 ⁇ L of the sample followed by keeping at 37° C. for 5 minutes and, at that stage, absorbance 1 was measured at the dominant wavelength of 600 nm and non-dominant wavelength of 700 nm. Then 60 ⁇ L of the reagent 4 were added followed by keeping at 37° C. for 5 minutes and, at that stage, absorbance 2 was measured at the dominant wavelength of 360 nm and non-dominant wavelength of 700 nm.
• Difference between the absorbance 1 and the absorbance 2 was calculated and converted to the amount of the sample using a control of known VLDL-cholesterol concentration as a standard solution.
• the control method used was as same as that in Example 1.
• Table 2 shows the result of assay using 30 cases of human serum. In the present method, the correlation coefficient was 0.997 (p ⁇ 0.05) and the result was good well coinciding with the control method.
• Reagent 3 MES buffer (pH 6.5) 50 mmol/L HDAOS 2.0 mmol/L Emulgen 913 (activator) 0.02% Sodium cholate (activator) 0.5% Calix[8]arene sulfate 10.0 mmol/L Bovine serum albumin 1.5% Ascorbic acid oxidase 3 U/mL Arginine 200 mmol/L Reagent 4 MES reagent (pH 6.5) 50 mmol/L Cholesterol oxidase 2 U/mL Cholesterol ester hydrolase derived 3 U/mL from Chromobacterium viscosum 4-Aminoantipyrine 10 mmol/L Sodium cholate 0.1% Peroxidase 15 U/mL
• the invention established as such provides a method for the assay of the component, particularly cholesterol, in VLDL which is one of serum lipoproteins and, since measurement of amount of the component, particularly cholesterol, in VLDL can be carried out selectively and easily, it is useful for clinical test, investigation, etc. for diseases which are related to lipoprotein such as hyperlipemia.

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• 2001
  • 2001-06-05 EP EP01934540A patent/EP1288306B1/fr not_active Expired - Lifetime
  • 2001-06-05 WO PCT/JP2001/004721 patent/WO2001094619A1/fr active Application Filing
  • 2001-06-05 US US10/297,241 patent/US6986998B2/en not_active Expired - Lifetime
  • 2001-06-05 DE DE60140251T patent/DE60140251D1/de not_active Expired - Lifetime
  • 2001-06-05 AU AU2001260714A patent/AU2001260714A1/en not_active Abandoned
  • 2001-06-05 AT AT01934540T patent/ATE446378T1/de not_active IP Right Cessation

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